The present invention relates to material handling systems, and more particularly to a program and method for designing and configuring a material handling system.
One type of material handling system that is found in a variety of factories, plants, and other environments is the automatic guided vehicle system. Automatic guided vehicles, or AGVs, are driverless vehicles that automatically carry or pull various loads of materials from one point to another point within an environment. These vehicles generally come in two different types: wire-guided and wireless AGVs. The wire-guided AGVs include sensors that allow the vehicles to follow energized wires buried in the floor of a facility. The wireless AGVs guide themselves without the use of wires. Some wireless AGVs occasionally detect update markers, which may be laser targets, magnets embedded in the floor, transponders, optical landmarks, or other devices which allow the vehicles to occasionally update their position within the facility.
AGV systems can also be broadly divided into another two categories: centrally controlled systems and distributed control systems. In a centrally-controlled AGV system, the movement of each AGV is controlled by a central controller. The central controller issues commands to the vehicles, such as telling them where to turn, what paths to follow, and what actions to take to avoid colliding with other vehicles. Distributed control AGV systems, in contrast, utilize AGVs that are capable of making many of their own decisions, such as where to turn, what paths to follow, and what actions are necessary to avoid colliding with other vehicles. These decisions are carried out by each individual vehicle, rather than a central controller that dictates their actions. Of course, some AGV systems can also be classified as hybrids of centralized and distributed control systems. Such systems include centralization of certain aspects and de-centralization of other aspects.
The installation and set-up of AGV systems in the pastxe2x80x94whether they have been centralized, de-centralized, wire, or wireless systemsxe2x80x94has often been a time-consuming and labor-intensive task. Virtually all AGV systems require a path to be laid out; traffic control logic or instructions to be determined; navigational information, such as the location of update markers, to be gathered and stored; and integration of the results of all of these tasks to be performed such that the system will function properly. In the past, these separate tasks have often been carried out manually, sometimes with different people working on different tasks or even different people working on the same task. This can lead to coordination problems where one person""s work may not be properly communicated to another person whose work is affected by the first person""s work. In such situations, design work may have to be re-done.
Besides these coordination difficulties, there is also a great deal of information that each person must know in order to accomplish the various design and installation tasks. For example, the people carrying out the system design tasks must know many details about the particular vehicles that are going to be installed. These details include the length and width of the vehicles, their turning radius, the length of any carts that will be towed behind the vehicles, the location of the vehicle""s guidepoint, the minimum stopping distance of a fully loaded vehicle, and other information. If someone does not know these details, they may design a system that causes the vehicle to bump into obstacles, that has too sharp of turns for the vehicles to follow, that requires the vehicles to stop faster than they are able, that does not cause the vehicles to precisely travel to the desired locations, or that otherwise causes the system to improperly function. Installing new AGV systems, or modifying existing systems, has therefore required extensive training of the personnel assigned to carry out such tasks. This results in increased costs to both the AGV system designer, who must spend money training these people, and the AGV system customers, who rarely have such trained personnel on staff and therefore must contract with the system designer whenever they desire to modify their AGV system.
The prior methods of AGV installation have also complicated the marketing aspects of selling AGV systems. When selling and installing AGV systems, the AGV installer often has a number of different people in contact with the customer at various levels. These may include one or more sales people, project engineers, design engineers, and/or technicians. If all these people do not sufficiently know all of the details about the intended system design, it is possible for a number of miscommunications to occur. Such miscommunications may involve misunderstanding the customer""s material handling requirements, making promises to the customer about the characteristics of the system that may not be possible to implement, or other miscommunications. The result of such miscommunications is often an increase in the costs of the design and installation process.
Another disadvantage of prior AGV system installation methods has been the uncertainty, until actual installation and testing, that the proposed system will actually meet the specified requirements. Customers of AGV systems often have timing requirements in which specified amounts material must be moved to different locations within a given amount of time. In complex AGV systems with large numbers of paths and large numbers of vehicles, it is often difficult to accurately predict how quickly material will get moved. If the initially installed system does not meet all of the specified requirements, changes may have to be made whose costs could have been otherwise mitigated if they had been part of the original system design. The advantages of a system designing process that mitigates these and other disadvantages can therefore be seen.
Accordingly, the present invention provides a method for installing AGV systems that simplifies the design and installation process. According to one of its various aspects, the present invention provides a central database of AGV and system information that minimizes the amount of training required for the system designers and installers. Pathways, traffic control, navigational information, and other system information are input into a computer in a simple, user-friendly manner, such as by way of a graphical interface. The computer is programmed to automatically perform certain design tasks, as well as to validate that the system design will function properly. The computer may be further programmed to simulate the movement of AGVs and material in a given environment to determine whether system requirements will be met or not.
According to a first embodiment of the present invention, a method for configuring a material handling system is provided. The method includes providing a computer having a visual display and inputting information into the computer that causes the computer to visually display at least a first path for a material handling vehicle. The method further includes inputting information into the computer to cause it to visually display at least one symbol representing at least one action location located at a position specified by the user. Further information is input into the computer that at least partially specifies what action will take place when the material handling vehicle reaches the action location. The computer is then used to create a computer file that contains the location of the path, the location of the action location, and the information that specifies what action will take place when the material handling vehicle reaches the action location. The computer file is transferred to a vehicle controller that is adapted to read the file and utilize the information contained therein to control the movement of the vehicle along the path and to control the action undertaken when the vehicle reaches the action location.
According to another aspect of the present invention, a method for configuring a material handling system is provided. The method includes providing a computer having a visual display and inputting into the computer path information that defines at least one path for a material handling vehicle. Information is also input into the computer that defines an action location and an action associated with that action location. The action associated with the action location is selected from the group consisting of: (a) determining whether a particular zone of the path is being occupied, and (b) determining which branch of the path a vehicle should follow at a path divergence. A computer file is created that contains the location of the path, the location of the action location, and the information that specifies what action will take place when the vehicle reaches the action location. The computer file is transferred to a vehicle controller adapted to read the file and utilize the information contained within the file to control the movement of the vehicle along the path and to control the action undertaken when the vehicle reaches the action location.
According to still another embodiment of the present invention, an apparatus is provided for graphically configuring a material handling system. The apparatus includes a computer, a visual display, a user interface device, and a vehicle controller. The visual display is in communication with the computer and is adapted to visually display information transmitted from the computer to the display. The user interface device is adapted to allow a user of the computer to input information that is displayed on the visual display. The computer is adapted to receive and display information from the user through the user interface that defines at least one path and at least one action location along the path. The computer is further adapted to receive and store information that at least partially specifies what action a material handling vehicle will take at the action location and to create a file containing the location of the path, the location of the action location, and the information that at least partially specifies what action will take place when the vehicle reaches the at least one action location. The vehicle controller is adapted to read the file and utilize the information contained within the file to control the movement of the vehicle along the path and to control the action undertaken when the vehicle reaches the action location.
According to yet another embodiment of the present invention, a method of configuring an automatic guided vehicle system is provided. The method includes providing a computer having a visual display and inputting information into the computer to cause the computer to visually display at least a first path for automatic guided vehicles. Information is also input into the computer that causes the computer to visually display a symbol representing a first action location and a symbol representing a second action location. The second action location is spaced from a first action location and defines a zone therebetween. Information is also input into the computer that causes a vehicle controller to check to see if the zone is occupied when a vehicle reaches either the first or second action location. A computer file is created that contains the location of the path, the location of the first and second action locations, and the information that causes the vehicle controller to check to see if the zone is occupied when a vehicle reaches either the first or second action locations. The computer file is transferred to the vehicle controller.
According to other aspects of the present invention, the information that is input into the computer may be input using a computer mouse, a track ball, a touch screen, a graphics tablet, or another type of device. The information may also be input into the computer such that it is graphically displayed over a floor plan of the environment in which the material handling system will operate. The computer may be programmed to allow the path which a vehicle will take from one destination to another destination to be highlighted when a user selects an arbitrary starting point and a destination. The computer may further be programmed to carry out a simulation of the movement of the automatic guided vehicles throughout a facility after the system has been sufficiently defined. The various aspects of the present invention simplify the overall design and implementation process of a material handling system. These and other benefits of the present invention will be apparent to one skilled in the art upon review of the following written description and the accompanying drawings.